By Jeff Goodell
December 22, 2016
In the late 1980s, James Hansen became the first scientist to offer unassailable evidence that burning fossil fuels is heating up the planet. In the decades since, as the world has warmed, the ice has melted and the wildfires have spread, he has published papers on everything from the risks of rapid sea-level rise to the role of soot in global temperature changes – all of it highlighting, methodically and verifiably, that our fossil-fuel-powered civilization is a suicide machine. And unlike some scientists, Hansen was never content to hide in his office at NASA, where he was head of the Goddard Institute for Space Studies in New York for nearly 35 years. He has testified before Congress, marched in rallies and participated in protests against the Keystone XL Pipeline and Big Coal (he went so far as to call coal trains "death trains").
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Right now, the Earth's temperature is already well into the range that existed during the Eemian period, 120,000 years ago, which was the last time the Earth was warmer than it is now. And that was a time when sea level was 20 to 30 feet higher than it is now. So that's what we could expect if we just leave things the way they are. And we've got more warming in the pipeline, so we're going to the top of and even outside of the Eemian range if we don't do something. And that something is that we have to move to clean energy as quickly as possible. If we burn all the fossil fuels, then we will melt all the ice on the planet eventually, and that would raise the seas by about 250 feet. So we can't do that. But if we just stay on this path, then it's the CO2 that we're putting up there that is a burden for young people because they're going to have to figure out how to get it out of the atmosphere. Or figure out how to live on a radically different planet.Right now, the Earth's temperature is already well into the range that existed during the Eemian period, 120,000 years ago, which was the last time the Earth was warmer than it is now. And that was a time when sea level was 20 to 30 feet higher than it is now. So that's what we could expect if we just leave things the way they are. And we've got more warming in the pipeline, so we're going to the top of and even outside of the Eemian range if we don't do something. And that something is that we have to move to clean energy as quickly as possible. If we burn all the fossil fuels, then we will melt all the ice on the planet eventually, and that would raise the seas by about 250 feet. So we can't do that. But if we just stay on this path, then it's the CO2 that we're putting up there that is a burden for young people because they're going to have to figure out how to get it out of the atmosphere. Or figure out how to live on a radically different planet.
And a sea level rise of a certain amount results in the sea coming much farther inland. Think of a right triangle, with the height being the sea level rise, and the hypotenuse being the show line. The hypotenuse is ALWAYS larger than the height. If the land rises gradually, the hypotenuse will be much larger.
Eg., if the land rises at an angle of 10 degrees, a rise in sea level of 20 feet will mean the sea will come 115 feet farther inland.
http://www.cleavebooks.co.uk/scol/calrtri.htm
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I think that our government has become sufficiently cumbersome in its support of R&D that I'd place more hope in the private sector. But in order to spur the private sector, you've got to provide the incentive. And that's why I'm a big supporter of a carbon fee.
Is the target of limiting warming to two degrees Celsius, which is the centerpiece of the Paris Agreement, still achievable?
It's possible, but barely. If global emissions rates fell at a rate of even two or three percent a year, you could achieve the two-degree target. People say we're already past that, because they're just assuming we won't be able to reduce missions that quickly. What I argue, however, is that two degrees is dangerous. Two degrees is a little warmer than the period when sea levels were 20 to 30 feet higher. So it's not a good target. It never had a good scientific basis.
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When I was working at NASA, I always felt I was working for the taxpayer. I was not working for the administration. When a new administration comes in, they think they can control public-information offices and science agencies and influence what they're saying so they become, in effect, offices of propaganda. But that's just wrong. When we have knowledge about something, we should not be prohibited from saying it as clearly as we can.
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